<style>
    /* 整体弹出框样式 */
    #bndg-popup-content {
        position: fixed;
        top: 20px;
        right: 120px;
        width: 320px;
        background-color: #f9f9f9;
        border: 1px solid #ddd;
        border-radius: 8px;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        z-index: 9999;
        font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
        display: flex;
        flex-direction: column;
    }

    /* 关闭按钮样式 */
    #bndg-popup-close {
        position: absolute;
        top: 8px;
        left: 8px;
        transition: color 0.3s ease;
        z-index: 1;
        /* 确保关闭按钮在最上面 */
    }

    #bndg-popup-close:hover {
        color: #333;
    }

    /* 结果显示区域样式 */
    #bndg-popup-result {
        padding: 20px;
        border-bottom: 1px solid #ddd;
        font-size: 18px;
        color: #333;
        height: 139px;
        overflow-y: auto;
        margin-top: 32px;
        white-space: pre-wrap; /* 保持空白符序列，但是正常地进行换行 */
        word-wrap: break-word; /* 在长单词或URL地址内部进行换行 */
        user-select: text; /* 允许文本选择 */
        -webkit-user-select: text; /* Safari 浏览器兼容 */
        /* 给result区域留出空间，避免覆盖close-button */
    }

    /* 输入容器样式 */
    .input-container {
        padding: 20px;
    }

    /* 输入框样式 */
    #bndg-popup-input {
        width: 100%;
        padding: 10px;
        font-size: 16px;
        border: 1px solid #ccc;
        border-radius: 4px;
        box-sizing: border-box;
        transition: border-color 0.3s ease;
    }

    #bndg-popup-input:focus {
        border-color: #007BFF;
        outline: none;
    }
</style>
<div id="bndg-popup-content">
    <span id="bndg-popup-close">
		<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 32 32">
		  <circle cx="16" cy="16" r="14" fill="none" stroke="#444" stroke-width="2"/>
		  
		  <line x1="8" y1="8" x2="24" y2="24" stroke="#444" stroke-width="2" stroke-linecap="round"/>
		  <line x1="24" y1="8" x2="8" y2="24" stroke="#444" stroke-width="2" stroke-linecap="round"/>
		</svg>
    </span>
    <div id="bndg-popup-result"></div>
    <div class="input-container">
        <input type="text" id="bndg-popup-input" placeholder="输入表达式如: 1.5+(2*5)^2" />
    </div>
</div>